Lithops, commonly known as "living stones," are succulent plants native to arid regions of southern Africa. They thrive in environments with minimal water, intense sunlight, and well-draining soil. To prevent mold and rot, it's crucial to replicate these conditions as closely as possible. Their natural adaptation to drought means they are highly susceptible to excess moisture, which can lead to fungal infections and rot.
The soil mix for Lithops must be extremely well-draining to avoid water retention. A blend of 80-90% inorganic materials (such as coarse sand, pumice, or perlite) and 10-20% organic matter (like cactus potting mix) is ideal. Avoid standard potting soil, as it retains too much moisture. Ensure the pot has drainage holes to allow excess water to escape, preventing root rot.
Overwatering is the primary cause of mold and rot in Lithops. Water only during their active growth periods (typically in autumn and spring) and avoid watering during dormancy (summer and winter). When watering, soak the soil thoroughly but allow it to dry completely before the next watering. Never let Lithops sit in standing water, as this encourages fungal growth.
Lithops require bright, direct sunlight for at least 4-6 hours daily. Insufficient light weakens the plant, making it more prone to rot. Ensure good air circulation around the plant to reduce humidity levels, which can promote mold growth. Indoors, a fan or open window can help, while outdoor plants should be placed in a breezy, sunny spot.
Lithops prefer warm, dry conditions. Avoid high humidity environments, as moisture in the air can settle on the plant and encourage mold. Ideal temperatures range between 65-80°F (18-27°C) during the day and slightly cooler at night. Protect Lithops from frost, as cold damage can weaken tissues and lead to rot.
Choose shallow pots with ample drainage holes, as Lithops have shallow root systems. Terracotta pots are ideal because they wick away excess moisture. Repot Lithops every 2-3 years to refresh the soil and inspect roots for signs of rot. During repotting, remove any dead or decaying material to prevent the spread of mold.
Regularly inspect Lithops for soft, discolored, or mushy spots, which indicate rot. If detected, immediately remove the affected parts with a sterile knife and allow the plant to dry in a shaded, well-ventilated area. Isolate infected plants to prevent the spread of mold to healthy specimens.
Use clean tools when handling Lithops to prevent introducing pathogens. Sterilize pots and tools with a diluted bleach solution before reuse. Avoid overcrowding plants, as this reduces airflow and increases humidity around the leaves, creating a favorable environment for mold.
